Jokes about the intelligence of two brothers being conditioned by birth order are common. Is the firstborn the most intelligent or, in fact, is it the other way around? In 1927, Austrian physician and psychologist Alfred Adler theorized that birth order in a family substantially affected a child’s personality, as parents treated their children differently depending on their age.
And if it is said, in popular belief, that in a family the older brother is more intelligent, responsible or extroverted; that the middle one is the most moderate and that the youngest is the most complicated in terms of personality, what does science say?
In a study developed by Rodica Damian and Brent W. Roberts, from the University of Illinois, in 2015, in the United States, which involved a sample of more than 377 thousand students, it was concluded that despite there being a cognitive difference between siblings, the order birth does not have a significant influence on the intellectual development of children in the same family.
“Birth order is one of the most widespread human experiences, thought to universally determine the degree of intelligence, friendliness, responsibility, sociability, emotional stability and openness to new experiences. The debate over the effects of birth order on personality has sparked ongoing interest for more than 100 years, both among the general public and scientists. And yet, despite a consistent stream of research, the results remain inconclusive and controversial. In the last year, two definitive documents have emerged that demonstrate that birth order has little or no substantial effect on personality”, can be read in the abstract of the study Settling the debate on birth order and personality.
